PC sales are expected to see a second half pop courtesy of Microsoft's Windows 8 and Intel's ultrabook push, but the long-term outlook is murky, according to IDC projections.

IDC noted that global PC shipments were up 1.8 percent in 2011 and will be 5 percent in 2012. The catch? IDC said that 2012 will be back-end loaded. Tech users are holding off on PC purchases as they are courted by tablets such as Apple's iPad, which moved 3 million units since March 16.

Jay Chou, analyst at IDC said:

2012 and 2013 will bring significant challenges for Microsoft and the PC community. Windows 8 and ultrabooks are a definitive step in the right direction to recapturing the relevance of the PC, but its promise of meshing a tablet experience in a PC body will likely entail a period of trial and error, thus the market will likely see modest growth in the near term.

The bigger question here is whether technology buyers---consumer and corporate---are going to have much patience for Wintel trial and error. PC sales are in a bit of a squeeze right now. Here are a few thoughts:

Windows 8 has put PC sales on standby.

Windows 8 has a new interface that may turn off users---or at least create a learning curve.

The software giant is melding the tablet and PC experience.

Ultrabook sales are also on standby pending Windows 8.

Those aforementioned items are significant wild cards for second half PC sales.

IDC is projecting that emerging market PC unit growth should be solid, but mature markets---notably Western Europe and the U.S.---are likely to see sluggish results. For instance, emerging markets will deliver PC shipment growth of 10.8 percent in 2013, but mature markets will come in with gains of 7.8 percent. That reality---emerging markets over mature ones---persists through 2016.